Works with Campaign Monitor

Verify your Campaign Monitor lists and mark every subscriber

Connect Campaign Monitor with your API key, pick a list, and ClearBounce checks every active subscriber. One click writes the result back to each subscriber as a custom field, so your next campaign can skip the addresses that would bounce.

100 free credits. No credit card required.

Integrations › Campaign Monitor Connected
Newsletter subscribers7 active subscribers

7 subscribers have never been checked.

SubscriberResultClearBounce Status in CM

Simulated. Nothing is sent, and no credits are used.

Connect with one API key

There’s nothing to install. ClearBounce reads your lists and updates subscribers through the Campaign Monitor API, using a key you can revoke at any time.

  1. 1
    Copy the key. In Campaign Monitor, click your profile image, then Account settings › API & integrations, and copy the API key.
  2. 2
    Paste it. In ClearBounce, open Integrations › Campaign Monitor and paste the key.
  3. 3
    Connect. Your lists appear with their active subscriber counts.

Managing several clients? An account API key shows the lists of every client, each labeled with the client’s name.

Account settings

API Key

This API allows other applications and tools to access this email account.

••••••••••••••••••••1Copy
Connect your Campaign Monitor account
2•••••••••••••••• 3Connect
Illustration based on Campaign Monitor’s API & integrations screen and the ClearBounce dashboard.

Verify a list, then write the results back

Each list shows when it was last verified. A run checks every active subscriber, and once it’s done one button writes the results to the subscribers in Campaign Monitor. Running the list again after an import only checks the new subscribers.

The Campaign Monitor page in the ClearBounce dashboard: a verified list with 3 deliverable, 2 undeliverable, 1 risky and 1 unknown subscriber, and 7 subscribers updated in Campaign Monitor
Screenshot of the ClearBounce dashboard after verifying a test list and writing the results back.

Two custom fields on every subscriber

The first time you write results to a list, ClearBounce creates two text fields on it. They’re hidden from the subscriber preference center, so your subscribers never see them.

ClearBounce Status
Deliverable, Undeliverable, Risky or Unknown.
ClearBounce Verified At
The date of the check, so you can re-verify old results on your own schedule.

Nothing else changes. ClearBounce never deletes, unsubscribes or resubscribes anyone, and subscriber names and other fields stay as they are.

A subscriber in Campaign Monitor with the custom fields ClearBounce Status set to Undeliverable and ClearBounce Verified At set to 2026-10-24
Screenshot of a test subscriber in Campaign Monitor after the results were written back.

Send only to the subscribers who’ll get it

Create a segment on the list, choose Custom fields › ClearBounce Status › matches exactly and enter Deliverable, then send your campaign to that segment. To keep everyone except the addresses that would bounce, use does not match exactly with Undeliverable instead.

Because the fields stay on the subscribers, the same segment keeps working for every campaign. Re-verify the list after big imports, and the new subscribers get their own result.

Campaign Monitor's segment builder with the rule Custom fields, ClearBounce Status, matches exactly, Deliverable
Screenshot of Campaign Monitor’s segment builder with a ClearBounce Status rule.

What to do with each result

Every subscriber comes back with one of four results. Deliverable is safe to send. For the other three, here’s what we’d do with a marketing list.

ResultWhat it meansOur suggestion
Undeliverable The address can’t receive mail: the mailbox doesn’t exist, the domain has no mail server, or it’s a typo like gmail.con. Leave out of every send. These are the addresses that bounce, and a high bounce rate hurts how inbox providers treat your campaigns.
Risky The address may work but is low quality: disposable inboxes, catch-all domains that accept anything, role addresses like info@, and likely typos. Leave out disposable inboxes. Keep catch-all and role addresses that signed up themselves. On B2B lists many company domains are catch-all.
Unknown ClearBounce couldn’t get an answer this time, usually because the recipient’s mail server was slow or temporarily refusing checks. Usually keep. Leaving them out drops real people whose mail server happened to be slow.

Not sure where to start? Send to everyone except Undeliverable, and compare your bounce rate with the last campaign.

Made for agencies running many clients

Campaign Monitor is built for agencies that send on behalf of their clients. The ClearBounce connection follows the same model, so one key covers the whole account.

  • Every client in one place

    Connect with your account API key and the lists of every client appear together, each labeled with the client’s name.

  • Clients’ lists stay theirs

    Results go into two hidden fields. Nobody is removed or unsubscribed, so each client decides what happens to their own subscribers.

  • Pay only for new subscribers

    Re-running a list skips subscribers that were already verified, so regular clean-ups only cost what was added since the last run.

Set it up in four steps

  1. Create a ClearBounce account

    Sign up free. Your account starts with 100 credits.

  2. Connect Campaign Monitor

    Copy your API key from Account settings › API & integrations in Campaign Monitor, then paste it on Integrations › Campaign Monitor in ClearBounce.

  3. Verify a list

    Click Verify list next to the list. ClearBounce imports its active subscribers and checks each one. Progress and results show on the same page.

  4. Write the results back

    Click Update subscribers in Campaign Monitor. Then create a segment where ClearBounce Status matches exactly Deliverable, and send to it.

Questions

Where do I find my Campaign Monitor API key?

In Campaign Monitor, click your profile image at the top right, then open Account settings and choose API & integrations. Copy the API key and paste it into ClearBounce. Don’t generate a new key unless you mean to, because that replaces the old one.

Which subscribers are checked?

The active subscribers of the list you pick. Unsubscribed, bounced and deleted subscribers are left out, and subscribers verified in an earlier run of the same list are skipped unless you choose to re-verify everyone.

Will ClearBounce remove or unsubscribe anyone?

No. It only writes the two ClearBounce fields. You decide who to leave out, usually with a segment on ClearBounce Status.

I manage several clients. Can I verify all of them?

Yes. With an account API key, ClearBounce lists the lists of every client, labeled with the client’s name, so you can clean them all from one place.

How many credits does it use?

One credit per subscriber checked. Writing the results back is free. Credits start at $4 per 1,000, never expire, and every new account gets 100 free. See pricing.

What data is sent to ClearBounce?

Only the email addresses of the list you verify, over HTTPS. Your API key is stored securely, used only for your lists, and you can revoke it in Campaign Monitor at any time. Details are in our privacy policy and DPA.

Your next Campaign Monitor send can go to a clean list

Create an account, connect Campaign Monitor, and start with 100 free credits.

More integrations: Mailchimp Moosend AcelleMail Zapier All integrations

Campaign Monitor is a product of Marigold. The Campaign Monitor name and logo belong to their owner.